Evaporator



EVAPORATOR v Filed July-1s, 19:57 svhefets-shet` 2 .l

1M, "IWF *9W l [Ill mi 6,5 l 67H 7'@ M M l L J uw] April 250 1939. l A CQNSTANTlNE l2,155,819

evaporator or boiler having refrigerated shelves Patented Apr. `'25,1939

PATENT oFFlcB v nvAPonAcron .Arthur It. Constantine, River Forest, lll., assigner to General Household Utilities Company, Chicago, Ill., a corporation of Delaware Application .my 1s, 1931, .serial N. 153,314 9 claims. (01."62-126) Mydinvention relates in general to evaporators.

or boilers and has more particular reference to the provisionof an evaporator of simplied and inexpensive construction and `designed especially for use in a refrigeration system.

-An important object of the present invention is to provide an evaporator of simplified construction and particularly well adapted for use in refrigeration systems ofthe compressor-con- `denser-evaporator type, such as are commonly utilized in domestic or household refrigerators.

Another important object is to provide an evaporator or boiler having refrigerated shelves and adapted for fabrication from a minimum number of standard or stock parts.

Another important object is to provide an fabricated by assembling a plurality of substantially identical plates providing internal ducts.l

Another important object is to form an evaporator having one or more refrigerated shelves, each formed from a plurality of similarly shaped pipes. v

Another important object is to provide an improved method of making evaporators for use in domestic or household refrigerators which consists in prefabricating a plurality of identical plates containing ducts and then assembling and securing the plates together to form side and bottom Vwalls and interior partitions or shelves, all of said side, bottom and partition walls comprising plates of substantially identical construction.

Another important object is to provide a refrigerant evaporator of the character, mentioned having simplied means for continuously ejecting a non-evaporable medium, such as oil, which may be carried into the evaporator' with the refrigerant.

Another important object is to form the side and bottom :walls of a refrigerant evaporator from a rectangular plate comprising a pair of sheet metal layers formed to provide internal refrigerant ducts between the layers by bending the plate to form spaced side walls and a bottom wall containing interconnected ducts, the evaporator including a separately formed header connected with the ducts ofthe side walls. y

Another object is to provide an evaporator having spaced side walls containing refrigerant circulating ducts and having hollow shelf form` ing means for the circulation of refrigerant therein, said shelf means being mechanically supported on and between the side walls with the refrigerant space of said shelf means connected with the refrigerant ducts of the side walls; a

'ing my present invention.

further object being to form the shelf means of pipe elements of substantially identical shape.

Another important object is to provide an evaporator having a header of simplified construction, the header comprising -a cylindrical 5 shell and being connected with the body of the evaporator by means of tubes extending between and secured to the walls of the cylindrical header-forming shell and the wail portions formin the remainder of the evaporator.

'Ihese and numerous other important objects, advantages, and inherent functions of the in. vention will become apparent as the same is more fully understood from f the following de-v scription, which, taken in connection with the 1l accompanying' drawings, discloses a preferred emr bodment of the invention.

Referring to the drawings:

Figure 1 is a perspective view of an evaporator embodying my present invention; t

Figure 2 is a plan view of one side of a prefabricated plate containing internal' ducts used in the construction of the evaporators shown'in Figure 1;'

Figure 3 is a plan view of the back of the 25 plate shown in Figure 2 illustrating the manner of forming the plate to produce evaporator side wall elements;

1 Figure 4 is a plan view of the back of the plate shown in Figure 2 Iillustrating the Amanner of 3 0 forming the plate for use as an evaporator partition or bottom wiill; l

Figure `5 is a top plan view of the evaporator Vshown in Figure 1;

Figure 6 is a front view ofthe evaporator 35 shown in section to reveal structural details;

Figures 7, 8 and 10 are sectional views respectively taken substantially along the line 1-1 in Figure 1, the line 8-8 in Figure 5, and the line 40 lll-I0 in Figure 6;

y Figure 9 is a sectional view similar to Figure 8 in order to illustrate a modified arrangement;

, Figure 11is a perspective view of a modified evaporator embodying my present invention;

Figure 12 is a sectional view taken substantially along the line |2I2 in Figure' 11; j

Figure 13 is a plan Iview of one side of a plate used in the evaporator assembly shown in Figure 11; and 5o Figure 14 is a perspective view of a shelf element which may be used in evaporators embody- To illustrate the invention, I have shownevaporators or boilers il comprising preferably Y,

sheet metal means arranged to form the side walls I3 and I5'and the bottom wall I1 of the evaporator.- 'I'he side and bottom walls are hollow to provide enclosed interconnected spaces for the circulation of an evaporable medium therein, and the evaporators also may include shelf means I9, preferably hollow and connected with the circulation spaces of the side walls I3 and |5 so that the evaporable medium may circulate-in the shelf neans also and refrigerate the same. vIn addition, the evaporators include "header means 51 preferably separately formed ating or evaporable medium.

It is an important feature of the' present invention to reduce the cost of making evaporators by forming these wall elements -I3, I5, I1, and I9 of substantially identical construction, and to this end each wall element comprises a pairof preferably sheet metal plates 2| and 23, the plate 2| being preferably at and having diagonally cut corners 25, and the plate 23 being formed with depressions 21 therein. The depressions 21 preferably comprise a plurality of spaced grooves or flutes 29 extending across the plate 23 and interconnected at the opposite ends of the grooves 29 by means of transverse grooves or utes 3|. The grooves 29 also are preferably interconnected by a transverse groove 33 extending intermediate the end connecting grooves 3| so that the arrangement of lgrooves 21 forms a grid-like pattern in the plates 23.

` 'I'he plates 2| and 23 are assembled in facing relationship with .the plate 2| closing the grooves 21 of the formed plate 23 so that said 'grooves form a network of internal ducts between the plates .2| and 23, which are secured together by folding the lateral edges 35 of the 'plate 2| around the marginal edges of the plate `23 and by welding, soldering, brazing, or otherwise sealing the plates together at their edges and also,

if desired, intermediate the grooved portions 29.

Thus arranged, the connected plates 2| and 23 form standard or stock units which may be utilized in fabricating the condenser II. 'Ihe units, however, require `certain additional drilling and'for'ming operations to condition the same for assembly as the side, bottom, and partitionl walls in the evaporator. To prepare a stock unit for use asthe side walls I3 and I5, I drill openings 31 in the plate 2| opposite one of the grooves 3|. Additional openings 39 are also formed in the plate 2| in position oppositetlie opposed ends of .the other groove 3|, similar openings `4I being 'Ihe groove 29 isolated insuch fashion is, for

clarity, identied bythe reference numeral 45.

In order to prepare the stock elements for use asa bottom or a. partition wall in the evaporator,

the plate 23 is' perforated as at 41 in the ribs or grooves 3| preferably opposite the ends of the end-most grooves 29. The element formingat least one of the walls I1 and I9 is also perforated as at 49, said perforation 49 preferably being' made in the element forming the bottom wall v I1 and being arrangedin the plate 23 of said element in a groove 29 at one end of the element opposite the ends of the connecting groove 33.

The elements I3, I5, I1, and I9 are assembled and secured in position with the plates 2| of the elements I3 and I5 in facing relationship,v the elements I1 and I9 being arranged between the facing surfaces of the elements I3 and I5 with the opposite edges of the elements I1 and I9 in position engaging the facing surfaces of said wall elements. The elements I1 and I9 also are preferably arranged with the plates 2| thereof facing upwardly in order to provide relatively smooth shelf surfaces in the evaporator. The plates I1 and I9 may be secured to the elements I3 and I5 in any preferred manner as by welding, soldering, brazing, or otherwise securing the edges upon the facing surfaces of the elements I3 and I5 and when so arranged the shelf elements form bracing means for holding and maintaining the side walls rigidly in spaced-apart, evaporatorforming relationship. The several duct systems ings 39 and 4I being disposed in registration with have ends projecting outwardly of the opposed edges of the elements I1 and I9 in position to fit in the openings 39.and 4| of the Wall elements I3 and I5 in order to facilitate the assembly operations whichmerely consist in mounting the elements I1 and I9 in position such that the ends of the tubes 5I extend in the openings 39 and 4I. Thereupon the tubes 5| may be sealed in the .openings 39 and 4I as by welding, soldering,

brazing, or otherwise; and it is not necessary to provide additional fastenings although I prefer to join the edges of the plates I1 and I9 throughout the entire extent thereof with the adjoining surfaces of the elements I3 and I5 whereby to additionally strengthen the assembled structure.

Th'e shelf means I9 may of course be made in various ways, and while Ivprefer to make it as a plate of the type shown in Figure 4, especially if the side and bottom walls are made of similar plates,l the shelf may however be conveniently and inexpensively made as 'shown in Figures 11, 12 and 14, wherein the shelf I9 comprises a pair of pipes 52 of preferably identical configuration. 1

These pipes preferably each comprise a long Land a relatively shorter end portion in axial alinement and an intermediate loop portion extending laterally of and interconnecting said end portions. Y l

The pipes 52 may be mounted by assembling lthe opposite ends of each pipe in the openings 4| in the opposing faces of the side wall elements- I3 and I5, with the loop of each pipe 52 extending toward vthe long end portion of the other. All portions of both pipes are arranged in a common plane or `zone and the pipe ends l Y -A ment 54 also may be embossed in any suitable are sealed as by silver soldering them in the openings 4|. The several looped portions of the pipes may be secured together or otherwise braced to strengthen and rigidify thesame. This may be accomplished in the illustrated embodiment by applying a shelf element 54, shown in Figure 14, upon the tubes 52. The element 54 has a fiat portion adapted to overlie the tubes andto which the tubes may be spot welded or otherwise secured. One edge of the element 54 may be curled as at 56 to fit upon the alined end portions of one of the tubes 52, and the opposite edge may be formed with a dependent flange 58 adapted to form a back stop for they shelf space immediately below the pipes 52. The eleor convenient manner to strengthen the same.

In Figures 11, 12- and 13 also I haveshown how the side walls I3 and I5 andthe bottom wall I1 may conveniently be fabricated as a unit by preforming a preferably rectangular plate 62 comprising a pair of preferably sheet metal layers 64 and 66.. .The layer 64 is or may be flat and formed with openings corresponding with theopenings 31 and 4| in the separate elements forming the side walls I3 and I5 in the embodiment shown in Figure 1. The other element 66 of the plate 62 is preferably embossed to form flutes corresponding with the utes 29, 3| and 33 in the several separate side and bottom wall elements of the embodiment illustrated lshelf I9, either of the sort shown in Figure 1 or the type illustrated in Figures 11, 12 and 14, may be applied as heretofore described.

The upper edges of the. side wall elements I3 and I5 may be secured together, in spaced apartl relationship and braced by cross members 53', preferably comprising strapsof sheet metal having lugs 55 by means of which the opposed ends of the strap members 53 may be welded or otherwise suitably secured to the upper edges of the wall elements |3 and I5. These strap members 53 may serve as handles for the convenient transportation of the evaporator and'may also provide vmeans for Ahanging the same in mounted?-v position as in a refrigerator cabinet. "i The evaporator, in addition to, the wall portions I3, l5, I1; and I9, comprises a header 51 formed as a cylindrical container, one end 59 L of which is preferably formed integralrwith the side walls of the container, the opposite end of the container being closed by meansof a separately formed cover 61| suitably` sealed thereon. The header 51 is pr'eferably'mounted in the evaporator assembly on and between the side wall elements |3, and |5, with thelongitudinal axis of the header 51 preferably extending at right angles with respect to the planes of said side wall elements, the header beingLLpreferably arranged substantiall'ymidway between the opposed ends of the evaporator. The header is attached' to the side walls and connected with the duct systems 21 of the sidewalls byfmeans of tubular connectors63, therepreferably being two connectors 63 at each end of the header for connecting the same with the adjacent lside w'all element of the evaporator. These connectors are of simple construction, comprising lengths of pipe curved intermediate the ends thereof so that the end portions of the `pipe extend at right angles. One end ofeach of the connectors 63 is fitted into and sealed in any preferred man- 'ner in an opening 65 in the lateral wall of the side wall'element on which the header is mounted so that the header 51 may be fabricated with the connectors 63 attached and then assembled in position between the side Wall elements I3 and I5 whereupon the connectors 63 may be sealed in place in position communicating with the openings 31.

The evaporator of my present invention is particularly adapted for usein refrigeration systems of the compressor-condenser-evaporator type which are commonly incorporated in domestic or household refrigerators. In such a refrigerating system, a suitable'refrigerating medium is enclosed in a circulating system including-a compressor in which the. medium in gaseous form is compressed, a condenser in which the compressed medium is liquefied, and an evaporator to which the liquefied medium is deliv ered for evaporation and heat absorption, the

refrigerant after evaporation in the evaporator being returned to the compressor fora repetition of the refrigerating cycle.

The evaporator of my present invention includes an inlet connection 65 for-introducing the refrigerant into the evaporating space' which,

of course, comprises the interconnected duct systems 21 of the several wall elements as -well as the space within the header which is con-` nected by means of the pipes 63 with the said interconnected duct systems. The inlet connection 65 comprises a tubular element or pipe. one end ofwhich is-provided with means 61 for connecting the samein the'delivery conduit of a refrigerant circulating system, the other end of said pipe being assembled and sealed in the opening 49, as clearlyshown in Figure 10. Thus, a suitable evaporable medium may be delivered within the refrigerating space 'at the lowermost point thereof since the opening 49 is preferably arranged in 'the bottom wall element I1, as shown in Figure 6. 'Ihe refrigerant is delivered through the inlet 65 directly into the connecting duct 33 of the wall element I1 and may escape thence A.through the ducts 29 into the end ducts 3| of the wall element I1. The refrigerant may then pass through the pipes 5| interconnecting the wall element I1 with the lowermost cross-duct 3| of the said side wallelements I3 and |5, whence .the refrigerant may pass upwardly through the ductsl 29 of side walls and into the upper crossducts 3| 'of 'said side walls and thence through the connectors 63 into theY header 51. Some of the evaporable medium, of course, in passing upwardly through the duct/system of the side Walls I3 and I5 may penetrate through the connectors 5| which join the partitionA wall element said side walls. i

-The refrigerant delivery system may be arranged to maintain the refrigerant in the evapo- .internal duct system ofthe partition I9 as well 75' co j as the duct system of the bottom wall I1. In accordance with my present invention, the evaporators provide an vunusually uniform refrigerating effect in all of the wall portions I3, I5, I1, and I9. Heat absorption' in a refrigerating system embodying the evaporator of my present invention is practically uniform in all the Wall surfaces of the evaporator. Upon starting the refrigerating system in operation with the evaporator extending in a humid atmosphere, it will be observed that frost commences to form on all of the heat transfer surfaces of the evaporator substantially simultaneously, thus indicating that the refrigerating effect is substantially uniform.

'I'he evaporator also includes an exhaust connection 13 comprising a pipe having an end 15 sealed in an opening 11 formed in the header 51, said end 15 opening within the header 51 at a level about the liquid level 1I. The exhaust vconnection 13 may be arranged as shown in Figure 8 with the end I5 opening downwardly into the header above the liquid level therein, or, as shown in Figure 9, the exhaust connection 13 may be arranged with its end 1 5 opening upwardly within the header above the liquid level therein.

The exhaust connection 131 may, of course, be provided with suitable means 19 connected thereon outwardly of the header and forming a connection for attaching the exhaust pipe with the suction side of a refrigerant circulating system.

Where the evaporator is used in a refrigerating system of the compressor-condenser-evaporator type in which it is necessary to provide adequate lubrication for the moving parts of the compressor, the refrigerating medium delivered to the evaporator may have `absorbed therein varying quantities of the medium utilized in lubricating the compressor. Such lubricating medium ordinarily does not evaporatel at the temperatures prevailing in refrigerant evaporators and consequently may become entrapped in the evaporator space, and if not removed may accumulate in such quantities as to seriously impair the operation of the evaporator. To this end, I have provided lmeans for continuously abstracting any non-evaporable substance which may find its way into the boiler along with the evaporable medium. As heretofore mentioned, one of the side walls of the evaporator may be formed as at'43 to provide an isolated groovev 45 comprising one of the grooves 29, such isolated groove 45 extending upwardly in the side walls and having a closed upper end. The oil extractor comprises a length of capillary tubing 8| which may be coiled as at 83 to accommodate the excess length of the tube vin small compass. 4One end of the tube sl is sea1ed as at a5 in an opening formed preferably in the upper side of the discharge pipe 13. The other end of the tube 8| is sealed in an opening 81 formed in the upper endofthe upstan/ding isolated duct 45.

When the evaporator is in operation liquid will be delivered in the isolated duct 45 normally to nsV an elevation above the opening 81 so thata portion of the liquid will enter the capillary tube 8| and bedrawn thence to the discharge pipe 13. The capillarity of the tube 8|, however, limits the amount of liquid that can thus' be withdrawn.

Th pipe 8|, however, provides for continuously extracting from the evaporator liquid'containing any non-evaporable substance which may reach the evaporator with the evaporable medium; consequently,l such non--evaporable substance is drawn vout ofthe evaporator and discharged through the outlet pipe13 in order to prevent the evaporatorfrom becoming filled with such nonevaporable substance. It will be noted that the capillary extractor tube 8| is exposed in the atmosphere surrounding the evaporator which, of course, will usually be higher than that prevail- ,ing in the liquid in the evaporator space. Liquid drawn into the tube 8| from the evaporator space and containing a non-evaporable substance dissolved or otherwiseO incorporated with the evaporable medium would, of course, be exposed to the temperature of the surrounding atmosphere during its passage through the tube. The evaporable constituent of the medium may evaporate in tube 8| leaving the non-evaporable substance in the form of successive slugs of liquid filling the tube, the successive slugs being separated by a quantity of the evaporable material in gaseous condition. These successive liquid and gaseous bodies, however. will be drawn through the tube and into the discharge pipe 13.

'I'he device of my present invention is relatively inexpensive to make since it embodies standard wall units of substantially identical constructionwhich may be readily formed to provide side,

bottom, and partition wall elements which may be easily assembled and secured together to form the unit since not only the side walls and bottom wall,

but" also the partition wall provide for the evaporation of the medium. I find that the particular arrangement which I have illustrated and described herein has an unusually uniform heat transferring effect throughout all of the surfaces of the wall elements, thereby promoting maximum evaporator eiliciency.

It is thought that the invention and its numerous attendant advantages will be understood from the foregoing description and it is obvious that numerous changes may be made in the form, construction, and arrangement of the several parts without departing from the spirit or scope of the invention and without sacrificing its attendant advantages, the forms herein described being preferred embodiments for the purposes of demonstrating the invention.

What 1 claim is new and desire to secure by Letters Patent of the United States is:

1. An evaporator or boiler comprising spaced jside wall elements and an intermediate partition or shelf element, said elements having substantially identical structural arrangement and comprising each'apairof cooperating plates formed communication with the duct systems of said side Wall elements.

2. An evaporator or boiler vcomprising spaced,"v

side wall elements and an intermediate partition or shelf element, said elements having substantially identical, structural arrangement and comprising each a pairof cooperating plates formed to provide therebetween a plurality of parallel grooves interconnected by transverse 'grooves at and intermediate the opposed ends oi the paral-` ing, the opposite ends of which are connected, re-

spectively, with the upper portions of the duct systems of said side Wall elements.

3. An evaporator or boiler comprising spaced side wall elements and an intermediate partition or shelf element, said elements having substantially identical structural arrangement'and comprising each a pair of cooperating plates formed to provide therebetween a plurality of parallel grooves interconnected by transverse grooves'at and intermediate the opposed ends of the parallel grooves to provide between the plates of each element a system of interconnected ducts, f

connector means communicating with the duct systems of said side wall elements through openings in the facing plates thereof and communicating with the duct system of the shelf element whereby to interconnect the duct systems of said elements, and means forming a header chamber in communication with the duct systems of said side wall elements by means of connector tubes opening laterally into the header, the said tubes being bent intermediate their ends for connection with the facing surfaces of said side wall elements.

4. An evaporator or boiler comprising spaced side wall elements-and an yintermediate partition or shelf element connected between the side v closing the grooves to form a system of interconnected ducts within the element, said shelf or partition element being assembled between the side wall elements with its opposed edges extending adjacent the opposing faces of said side `wall elements opposite a-transverse groove of each of said side wall elements, means interconnecting each of a pair of the transverse grooves of said shelf or partition element respectively with a transverse groove of each of said side Wall ele- A ments, and means forming afheader chamber interconnected with the duct systems of said side wall elements.

5. An `evaporator on boiler comprising spaced side wall elements and a plurality of intermediate partition elements including a bottom wall element and a shelf element, the shelf element being connected between the side wall elements in vertical spacement with respect to the bottom wall element, said elements having substantially identical structural arrangement and comprising each a pair of cooperating plates formed to provide therebetween a plurality of parallel grooves interconnected by transverse grooves at and intermediate the opposed ends ofthe parallel grooves to provide between the plates o; ea l 1 el ment a system of interconnected ducts, the duct systems of said.partition elements being connected each with the duct systems of both of said sidewall elements, said partition walls being assembled between the side wall elements each 5 with its opposed edges `in position substantially registering with corresponding transverse grooves in said side wall elementsand tubular connectors sealed upon said partition and side wall ele- .ments and communicating one of the transverse l()l grooves of the partition wall with a transverse groove of a side Wall and communicating another transverse groove of the partition Wall with a transverse groove of the other side wall.

6. An evaporator or boiler comprising spaced 15 side wall elements of substantially identical construction, each comprising a pair of cooperating sheet-metal portions -formed to provide therebetween a plurality of parallel, vertically extending ducts in said side wall elements intercon- 20 nected by a transverse duct at the upper end of said parallel ducts to form an interconnected duct system in each of said side wall elements,

ymeans interconnecting said duct systems below the transverse ducts; means forming a header 25 rchamber connected to the transverse duct of each side wall element, at least one of said side wall elements being formed to isolate the upper end of at least one of said duct portions, means forming an outlet on said header, and means forming a capillary channel connecting the upper end of said isolated duct with said outlet.

7. An evaporator or boiler comprising spaced side wall elements of substantially identical construction, each comprising a pair of cooperating sheet-metal portions formed to provide therebetween a plurality of parallel, vertically extending ducts in said side wall elements interconnected by a transverse duct at the upper end of said parallel ducts to form an interconnected duct system in each of said side wall elements, means interconnecting said duct systems below the transverse ducts, means forming a header chamber connected to the transverse duct oi.' each side wall element, at least one of said side Wall elements being formed to isolate the upper end of at least one of said duct portions, means forming an outletv on said header, and means forming a capillary channel lconnecting the upper end of -said isolated duct `with said outlet and comprising a tube connected atits opposite ends in said isolated duct portion and in said outlet and having the intermediate portions of the tube arranged in coils.

f 8. An evaporator or boiler comprising spaced side Wall elements of substantially, identical con-l struction, each comprising a pair of cooperating sheet-metal portions formed to provide therebetween a plurality of parallel, vertically ex- 60 tending ducts in said side wall elements interconnected by a transverse duct at.the upper end of said parallel ducts to form an interconnected duct system in each of said side Wall elements, means interconnecting said duct' systems. below 65 theitransyerse ducts, means forming a header chamber connected to the transverse duct of each side wall element, at least one of said side wall elements being formed to isolate the upper endy of at least one of said duct portions, means form-7^rr 70 ing an outlet on said header, and means forni-"-y ing a capillary channel connecting the upper end of said isolated duct. with said outlet, said capillary channel forming means comprising a 15H-billar element connected at one end in said 7s isolated duct portion and connected at the other Aend in the upperside of said outlet.

9. An evaporator or boiler comprising 'spaced side wall elements and an intermediate partition ranged with the dat plates thereof in facing relationship and said shelf element being arranged between the side wall elements with the fiat plate'of the shelf element facing upwardly between the side wall elements, meansinterconnecting the duct systems of the shelf andl side wall elements and header forming means interconnected with the duct system of each of said side wall elements, an outlet or suction connection on said header and an inlet connection on one of said shelf forming elements and communicating with the duct system thereof.

AR'I'H'UR R. CONSTANTINE. 

